title: Chaperones as thermodynamic sensors of drug-target interactions reveal kinase inhibitor specificities in living cells.
abstract: The interaction between the HSP90 chaperone and its client kinases is sensitive to the conformational status of the kinase, and stabilization of the kinase fold by small molecules strongly decreases chaperone interaction. Here we exploit this observation and assay small-molecule binding to kinases in living cells, using chaperones as 'thermodynamic sensors'. The method allows determination of target specificities of both ATP-competitive and allosteric inhibitors in the kinases' native cellular context in high throughput. We profile target specificities of 30 diverse kinase inhibitors against >300 kinases. Demonstrating the value of the assay, we identify ETV6-NTRK3 as a target of the FDA-approved drug crizotinib (Xalkori). Crizotinib inhibits proliferation of ETV6-NTRK3-dependent tumor cells with nanomolar potency and induces the regression of established tumor xenografts in mice. Finally, we show that our approach is applicable to other chaperone and target classes by assaying HSP70/steroid hormone receptor and CDC37/kinase interactions, suggesting that chaperone interactions will have broad application in detecting drug-target interactions in vivo.
authors.affiliation: Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, USA.
authors.forename: Mikko
authors.initials: M
authors.lastname: Taipale
authors.forename: Irina
authors.initials: I
authors.lastname: Krykbaeva
authors.forename: Luke
authors.initials: L
authors.lastname: Whitesell
authors.forename: Sandro
authors.initials: S
authors.lastname: Santagata
authors.forename: Jianming
authors.initials: J
authors.lastname: Zhang
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Liu
authors.forename: Nathanael S
authors.initials: NS
authors.lastname: Gray
authors.forename: Susan
authors.initials: S
authors.lastname: Lindquist
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D000077547:Crizotinib; D017277:Drug Approval; D004347:Drug Interactions; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D051379:Mice; D018832:Molecular Chaperones / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D010770:Phosphotransferases / Q000037:antagonists & inhibitors; D011485:Protein Binding; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D050783:Proto-Oncogene Proteins c-ets / Q000378:metabolism; D011720:Pyrazoles / Q000627:therapeutic use*; D011725:Pyridines / Q000627:therapeutic use*; D020812:Receptor, trkC / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D013379:Substrate Specificity; D023041:Xenograft Model Antitumor Assays; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D018797:Cell Cycle Proteins; D000077547:Crizotinib; D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; D010770:Phosphotransferases; D047428:Protein Kinase Inhibitors; D050783:Proto-Oncogene Proteins c-ets; D011720:Pyrazoles; D011725:Pyridines; D020812:Receptor, trkC; D012097:Repressor Proteins; D000097764:ETS Translocation Variant 6 Protein